The present invention relates to a gearshift operating device of the type provided in an automatic manual transmission (hereinafter referred to as an AMT) for automatically performing a gearshift operation of a transmission having a synchro-mechanism or a dog-clutch; and, more particularly, the invention relates to speedup of the gearshift operation and realization of miniaturization and lightweight formation of the device.
Generally, a gearshift operating device which is used to perform the shift selection operation of a normally contact-mesh type transmission has a shift finger which selectively engages to a plurality of shift fork shafts so as to join or dejoin a gear, an actuator for driving the shift finger in the shift direction, a sensor for detecting a displacement of the shift finger in the shift direction, an actuator for driving the shift finger in the selection direction, and a sensor for detecting a displacement of the shift finger in the selection direction. Individual actuators (for example, a motor) for performing these operations in the shift direction and selection direction, respectively, can be electrically controlled and can independently perform the shift operation (joining and dejoining of the gear) and the selection operation (selection of the shift fork shafts), respectively.
On the other hand, in a normally contact-mesh type transmission, a shift pattern, which is known as type H or double H, is generally widespread, and, in such a device, the shift finger draws a trace following the alphabetic character H to perform the shift and selection operations. Namely, the shift finger operates in a direction parallel to the shift fork shaft to perform the shift operation (joining and dejoining of the gear); and, in the neutral position, it operates in a direction perpendicular to the shift operation to perform the selection operation. See, for example, Patent Document 1 (Japanese Application Patent Laid-open Publication No. 2001-141047 (pages 4 and 5, FIG. 3)).
In the aforementioned gearshift operating device, the actuators performing the shift operation (joining and dejoining of the gear) and the selection operation are sequentially operated, so that the operation of switching the gear takes a lot of time. Namely, when switching gears, the motor for the shift operation is driven first to disengage the gear; and, then, when the gear is set in the neutral position, the motor for the selection operation is driven. When the shift finger is set in a position relating to the joining and dejoining part of a desired shift fork shaft, the motor for the shift operation is driven to push the shift fork shaft into the gear joining position.
In this operation, to perform the gear dejoining operation, the shift motor is accelerated and decelerated, and to perform the selection operation, the selection operation motor is accelerated and decelerated, and to perform the gear joining operation finally, the shift motor is again accelerated. In the case of accelerating and decelerating the motor three times in one gearshift operation in this way, the gearshift time can not be shortened, and there is a possibility that the power consumption may be increased. The length of time required for the gearshift operation contributes in actual car operation to a problem of uncomfortableness in the ride at the time of gearshift operation or a speed up of the engine (an increase in fuel expenses).
Further, the conventional gearshift operating device is generally large in shape and heavy in weight, so that it is difficult to mount in a car having a small space around the transmission, like a small-sized car.